The U.S. Internal Revenue Service, which is supposed to get paid this time of year, will be shelling out millions of dollars to Microsoft for extended Windows XP support, according to a ComputerWorld report.

In case you haven't heard yet, the software giant has officially pulled the plug on Windows XP, one of the most popular Windows versions, launched more than 12 years ago. The company has said that it will not provide support or security updates for the venerable operating system.

Of course, it will continue to provide "custom support" to those who haven't yet migrated from XP to a more modern operating system, and IRS will be one of them. Out of the agency's approximately 110,000 Windows-powered desktops and notebooks, only 47% have been upgraded to Windows 7, while the remaining are still running Windows XP.

"The IRS is working to complete the updates [to Windows 7] by the end of calendar year 2014", an IRS spokesperson said.

John Koskinen, commissioner of the IRS, said that the delay in migration happened because the agency had $300 million worth of IT improvements on hold due to budget issues. One of those improvements was the XP-to-7 migration, for which $30 million were allocated.

Microsoft currently charges $200 per PC for the first year of Custom Support. This means that the government agency would pay the company $11.6 million for one year of Custom Support, the report notes. The remaining $18.4 million would be used to buy new PCs to replace the oldest ones running XP.